Shoulder Infections Clinical Trial
Official title:
Can Propionibacterium Acnes Load in Primary Shoulder Surgery be Reduced With Preoperative Application of a Benzoylperoxid/Miconazolnitrat crème Additional to Standard Antibiotic Prophylaxis
60 patients undergoing first time open shoulder surgery (Latarjet, prosthesis) will be prospectively included in this study. The investigators will do a randomized controlled trial, choosing with a single-blinded protocol 30 patients for local therapy and other 30 patients as the control group without any treatment preoperative. In the preoperative consultation 30 patients will get Acne Crème Plus (Benzoylperoxid and Miconazolnitrat) to apply until operation (on average 7 days) after receiving written consent. The application should be done daily in the evening on the planned operative side covering the skin from the nipple-areola complex laterally to the medial margin of the scapula and from a horizontal line through the nipple-areola complex cranially over the shoulder and dorsally to the spina scapulae. 30 patients will be included in the control group. Those patients will not get the local therapy in the preoperative consultation but they will need to give written consent for taking swabs for culture samples pre- and intraoperative. In the operation room there will be done from each of the 60 patients a superficial skin swab before doing disinfection, a swab of the subcutaneous layer and a swab of the deep layer (joint capsule). All the three swabs from each of the 60 patients will be sent to Unilabs, Labor für Medizinische Analytik AG, Dübendorf, Switzerland to streak on agar plates to cultivate under anaerobic conditions for 14 days. Propionibacterium acnes will be identified by use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.
According to recent studies, Propionibacterium acnes is found in 30% of patients with no
preliminary shoulder operation and without obvious signs of infection. This bacterium is
supposed to be the main pathogen causing shoulder infections. As it resides in the
subcutaneous layer, many antiseptic and antibiotic agents that affect other layers fail to
prevent infections. When administering antibiotics to reduce infections due to
Propionibacterium acnes, cross-resistances to various antibiotics are created. Therefore, the
investigators aim to investigate the efficacy of a local combination therapy without
antibiotics (Benzoylperoxid and Miconazolnitrat) to reduce the presence of Propionibacterium
acnes in patients first time undergoing open shoulder surgery. The investigators will also
demonstrate the rate of positive cultures for Propionibacterium acnes in different layers
regarding gender and age of patients. To best knowledge, no randomized controlled trials
investigating the efficacy of Benzoylperoxid and Miconazolnitrat for reduction of
Propionibacterium acnes in patients undergoing first time open shoulder surgery exist in the
literature. However, in 1989 a clinical trial could demonstrate a 66% reduction of
inflammatory acne lesions by applying a lotion containing Benzoylperoxid and Miconazol.
The investigators suppose that the patients with the local therapy (therapy group) show fewer
positive samples than the patients of the control group as the combination of Benzoylperoxid
and Miconazolnitrat (Widmer Acne Crème Plus, approval number 47033, Swissmedic) is used in
the therapy of acne where Propionibacterium acnes is the major pathogen. By decreasing the
presence of Propionibacterium acnes, infections and revision surgeries could be reduced as
well. The investigators expect a higher rate of positive cultures from the subcutaneous layer
compared to the superficial and to the deep layer. The investigators await more positive
cultures in men than in women as men show a higher density of the glands in the subcutaneous
layer where Propionibacterium acnes is linked to. For the same reason, the investigators
suppose also a higher number of positive culture samples in younger patients (≤40 years) than
in older patients (>40 years).
60 patients undergoing first time open shoulder surgery (Latarjet, prosthesis) will be
prospectively included in this study. The investigators will do a randomized controlled
trial, choosing with a single-blinded protocol 30 patients for local therapy and other 30
patients as the control group without any treatment preoperative. In the preoperative
consultation 30 patients will get Acne Crème Plus (Benzoylperoxid and Miconazolnitrat) to
apply until operation (on average 7 days) after receiving written consent. The application
should be done daily in the evening on the planned operative side covering the skin from the
nipple-areola complex laterally to the medial margin of the scapula and from a horizontal
line through the nipple-areola complex cranially over the shoulder and dorsally to the spina
scapulae. 30 patients will be included in the control group. Those patients will not get the
local therapy in the preoperative consultation but they will need to give written consent for
taking swabs for culture samples pre- and intraoperative. In the operation room there will be
done from each of the 60 patients a superficial skin swab before doing disinfection, a swab
of the subcutaneous layer and a swab of the deep layer (joint capsule). All the three swabs
from each of the 60 patients will be sent to Unilabs, Labor für Medizinische Analytik AG,
Dübendorf, Switzerland to streak on agar plates to cultivate under anaerobic conditions for
14 days. Propionibacterium acnes will be identified by use of matrix-assisted laser
desorption/ionization time-of-flight mass spectrometry. The number of positive culture
samples from the therapy group will be compared with the number of positive culture samples
from the control group.
Determination of Sample Size was done by performing a power analysis using www.clincalc.com,
a sample size calculator placed at disposal by Sean P. Kane (clinical pharmacist, assistant
professor at Rosalind Franklin University of Medicine and Science, North Chicago and advocate
of evidence-based medicine). The study groups are two independent groups as they receive
different treatments. The primary endpoint is dichotomous. The anticipated incidence of the
therapy group is defined as 30%, the incidence of the control group is supposed to be 3-5%
and the enrolment ratio is 1. The probability of a type-I-error is 0.05. With obtaining a
power of 80%, between 56 and 70 participants are needed for the study according to the sample
size calculator.
Recent studies could show that 30% of the patients without any obvious signs for infection
and no preliminary operation have positive culture samples for Propionibacterium acnes, the
investigators expect this result as well. The investigators suppose that the patients with
the local therapy (therapy group) show fewer positive samples than the patients of the
control group as the combination of Benzoylperoxid and Miconazolnitrat is used in the therapy
of acne where Propionibacterium acnes is the major pathogen. As it is known that
Propionibacterium acnes resides in the subcutaneous layer, the investigators expect a higher
rate of positive cultures from the subcutaneous layer compared to the superficial and to the
deep layer. The investigators expect more positive cultures in men than in women as men show
a higher density of the glands in the subcutaneous layer where Propionibacterium acnes is
linked to. The investigators suppose also a higher number of positive culture samples in
younger patients (≤40 years) than in older patients (>40 years).
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